I need help!! This year we prepared a acre 3 acre food plot, first round-up was applied and after about 10 days it was plowed. Disc and dragged and then planted. We used seed from NWTF which was I think a Strut and Rut mix. It looked good as it started, but since has turned into a weed field. I mean weeds!!! At this point should we brush hog it? I know a herbacide would help, but after the round-up, why and where did all the weed come from?